As electronic technology and communication network have been continuously developed, hardware, software, and operating features of video conferencing are notably enhanced. The current video conferencing allows users to see other's motion through screens and thereby provides a realistic telepresence experience in communication. However, there exists a gap between the video conference and a real conference where all participants are sitting together. The main reason is because the center of a display of a video conferencing system (i.e. normally would be a display area of another participant's facial image) and a configuration position of a video capturing device are not the same so that the participants never appear to make eye contact with each other or appear tilted. Thus, the participants would be hardly concentrated on the conversation.